The Tube MP Studio V3 is a single channel tube based microphone preamp that builds on the success of the original Tube MP but with added features. Primarily, the unit features V3 technology which provides optimized reference points - presets that allow the user to select between preamp settings designed for guitars (electric and acoustic), keyboards, bass guitars, drums, vocals and more. Also included is OPL (Output Protection Limiter), which precisely and accurately controls and maintains the output peak signal. While it's primary function is as a microphone preamp, the Tube MP Studio V3 is also a great direct box - impedance matching, amplifying and improving the sound of any instrument. Additionally the usage of external mic/line preamps has become increasingly popular over the past several years. The unit offers better performance and sound quality over that which can obtained from the "on-board" preamps included in many of today's low-cost mixers and multi-track recorders.